Photographic developer with alkali substitute



Patented Sept. 5, 1933 UNITED STATES PHOTOGRAPHIC DEVELOPER WITH ALKALI SUBSTITUTE Merle L. Dundon, Rochester, N. Y., assignor to Eastman Kodak C0mpany, R0chester, N. Y., a corporation of New York No Drawing. Application February 2, 1932 Serial No. 590,520

6 Claims.

This invention relates to a photographic developer and particularly to one in which the usual alkalies are substituted by a class of compounds new for the purpose.

Alkaline developers have now been known and used for many years. These developers usually contain developing agents, a so-called preservative, such as sodium sulphite, and alkalies, such as sodium or potassium carbonates, or sodium or potassium hydroxides. In recent years various sensitive materials and photographic processes have appeared with which the use of these stronger alkalies is objectionable for one reason or another. It is an object of this invention to provide substances which may be used in a photographic developer in place of these stronger alkalies and to provide developers giving satisfactory results without the objectionable features of those containing the alkalies previously used.

Substances which I have found suitable as alkali substitutes are the alkyl amines, particularly those containing one or more hydroxy alkyl groups. Triethanolamine and its homologues are representative examples. Of this preferred class of substances the following are especially useful:

1. Monoethanolamine ./H N-GHzCHzOH H 2. Diethanolamine /H NCH2CH2OH omcmon 3. Triethanolamine 4. fl diethylamino ethyl alcohol 5. Tri-n-propylamine CHzCHzCHa The. following formulas will serve to illustrate my invention:

is commercially I Example I Monomethylparaminophenol sulphate 2 grams Hydroquinone Sgrams Sodium sulphite 100 grams Triethanolamine, 90% solution 2 c. 0. Water to 1 liter Example II Monomethylparaminophenol sulphate 0.75 grams Hydroquinone 3.75 grams Sodium sulphite 30.0 grams Triethanolamine, 90% solution 15 c. 0. Water to 1 liter In formulas such as these, triethanolamine acts not only as an alkali, but prevents excessive sludging in the developer.

Some of the substances included in my broad definition are not useful because they are not sufficiently soluble in the developer. Thus, the homologues of triethanolamine above propanolamine are not sufficiently soluble to be useful. The tertiary amines,

in which each R is an alkyl group, are soluble when each alkyl group does not contain more than 3 carbon atoms. The soluble compounds, however, function very satisfactorily.

I consider as included in my invention all modifications and equivalents coming within the scope of the appended claims.

What I claim is:

1. A photographic developer comprising a developing agent and a compound having the general formula R where any R may be an alkyl group. or an hydroxy alkyl group, and X is a hydroxy alkyl group.

a de- MIERLE L. DUNDON.

2. A photographic developer comprising a de- 

